From: Ray Strode <rstrode@redhat.com>
Date: Tue, 5 May 2009 15:57:21 +0000 (-0400)
Subject: [event-loop] Don't crash by running removed timeouts
X-Git-Tag: 0.7.0~190
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=79baa323e61b4c8a0e7bf75c773e78094ebf27fa;p=thirdparty%2Fplymouth.git

[event-loop] Don't crash by running removed timeouts

We used to run and remove timeouts in a loop.  This
breaks the case where the dispatched timeout handler
removes the timeout itself.

We fix it by making timeout handling a two pass thing.
First we find which handlers need to be dispatched,
and move them to their own list.  Then we run through
the new list and dispatch the handlers.
---

diff --git a/src/libply/ply-event-loop.c b/src/libply/ply-event-loop.c
index 5bfd4062..8f6b3044 100644
--- a/src/libply/ply-event-loop.c
+++ b/src/libply/ply-event-loop.c
@@ -1123,6 +1123,7 @@ ply_event_loop_disconnect_source (ply_event_loop_t           *loop,
 static void
 ply_event_loop_handle_timeouts (ply_event_loop_t *loop)
 {
+  ply_list_t *watches_to_dispatch;
   ply_list_node_t *node;
   double now;
 
@@ -1130,6 +1131,8 @@ ply_event_loop_handle_timeouts (ply_event_loop_t *loop)
 
   now = ply_get_timestamp ();
   node = ply_list_get_first_node (loop->timeout_watches);
+
+  watches_to_dispatch = ply_list_new ();
   loop->wakeup_time = PLY_EVENT_LOOP_NO_TIMED_WAKEUP;
   while (node != NULL)
     {
@@ -1142,8 +1145,7 @@ ply_event_loop_handle_timeouts (ply_event_loop_t *loop)
       if (watch->timeout <= now)
         {
           assert (watch->handler != NULL);
-          watch->handler (watch->user_data, loop);
-          free (watch);
+          ply_list_append_data (watches_to_dispatch, watch);
           ply_list_remove_node (loop->timeout_watches, node);
         }
       else {
@@ -1156,6 +1158,23 @@ ply_event_loop_handle_timeouts (ply_event_loop_t *loop)
       node = next_node;
     }
 
+  node = ply_list_get_first_node (watches_to_dispatch);
+  while (node != NULL)
+    {
+      ply_list_node_t *next_node;
+      ply_event_loop_timeout_watch_t *watch;
+
+      watch = (ply_event_loop_timeout_watch_t *) ply_list_node_get_data (node);
+      next_node = ply_list_get_next_node (loop->timeout_watches, node);
+
+      watch->handler (watch->user_data, loop);
+      free (watch);
+
+      node = next_node;
+    }
+
+  ply_list_free (watches_to_dispatch);
+
 }
 
 static void